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Applies to SUSE Linux Enterprise Server 12 SP3

2 The Control File Edit source

2.1 Introduction Edit source

The control file usually is a configuration description for a single system. It consists of sets of resources with properties including support for complex structures such as lists, records, trees and large embedded or referenced objects.

Important
Important: Control Files from Previous Releases are Incompatible

A lot of major changes were introduced with SUSE Linux Enterprise Server 12 SP3 (the switch to systemd and GRUB 2 for example). These changes also required fundamental changes in AutoYaST, therefore you cannot use AutoYaST control files created on previous SUSE Linux Enterprise Server versions to install SUSE Linux Enterprise Server 12 SP3 and vice versa.

2.2 Format Edit source

The XML configuration format provides a consistent file structure, which is easy to learn and to remember when attempting to configure a new system.

The AutoYaST control file uses XML to describe the system installation and configuration. XML is a commonly used markup, and many users are familiar with the concepts of the language and the tools used to process XML files. If you edit an existing control file or create a control file using an editor from scratch, it is strongly recommended to validate the control file. This can be done using a validating XML parser such as xmllint or jing, for example (see Section 3.3, “Creating/Editing a Control File Manually”).

The following example shows a control file in XML format:

Example 2.1: AutoYaST Control File (Profile)
<?xml version="1.0"?>
<!DOCTYPE profile>
<profile
  xmlns="http://www.suse.com/1.0/yast2ns"
  xmlns:config="http://www.suse.com/1.0/configns">
  <partitioning  config:type="list">
    <drive>
      <device>/dev/sda</device>
      <partitions config:type="list">
        <partition>
          <filesystem config:type="symbol">btrfs</filesystem>
          <size>10G</size>
          <mount>/</mount>
        </partition>
        <partition>
          <filesystem config:type="symbol">xfs</filesystem>
          <size>120G</size>
          <mount>/data</mount>
        </partition>
      </partitions>
    </drive>
  </partitioning>
  <scripts>
    <pre-scripts>
      <script>
        <interpreter>shell</interpreter>
        <filename>start.sh</filename>
        <source>
        <![CDATA[
#!/bin/sh
echo "Starting installation"
exit 0

]]>

        </source>
      </script>
    </pre-scripts>
  </scripts>
</profile>

2.3 Structure Edit source

Below is an example of a basic control file container, the actual content of which is explained later on in this chapter.

Example 2.2: Control file container
<?xml version="1.0"?>
<!DOCTYPE profile>
<profile
  xmlns="http://www.suse.com/1.0/yast2ns"
  xmlns:config="http://www.suse.com/1.0/configns">
  <!-- RESOURCES -->
</profile>

The <profile> element (root node) contains one or more distinct resource elements. The permissible resource elements are specified in the schema files

2.3.1 Resources and Properties Edit source

A resource element either contains multiple and distinct property and resource elements, or multiple instances of the same resource element, or it is empty. The permissible content of a resource element is specified in the schema files.

A property element is either empty or contains a literal value. The permissible property elements and values in each resource element are specified in the schema files

An element can be either a container of other elements (a resource) or it has a literal value (a property); it can never be both. This restriction is specified in the schema files. A configuration component with more than one value must either be represented as an embedded list in a property value or as a nested resource.

2.3.2 Nested Resources Edit source

Nested resource elements allow a tree-like structure of configuration components to be built to any level.

Example 2.3: Nested Resources
...
<drive>
  <device>/dev/sda</device>
  <partitions> <!-- this is wrong, explanation below -->
    <partition>
      <size>10G</size>
      <mount>/</mount>
    </partition>
    <partition>
      <size>1G</size>
      <mount>/tmp</mount>
    </partition>
  </partitions>
</drive>
....

In the example above the disk resource consists of a device property and a partitions resource. The partitions resource contains multiple instances of the partition resource. Each partition resource contains a size and mount property.

The XML schema defines the partitions element as a resource supporting one or multiple partition element children. If only one partition resource is specified, it is important to use the config:type attribute of the partitions element to indicate that the content is a resource, in this case a list. Using the partitions element without specifying the type in this case will result in undefined behavior, as YaST will incorrectly interpret the partitions resource as a property. The example below illustrates this use case.

Example 2.4: Nested Resources with Type Attributes
...
<drive>
  <device>/dev/sda</device>
  <partitions config:type="list">
     <partition>
        <size>10G</size>
        <mount>/</mount>
     </partition>
     <partition>
        <size>1G</size>
        <mount>/tmp</mount>
     </partition>
  </partitions>
</drive>
....

2.3.3 Attributes Edit source

Global attributes are used to define metadata on resources and properties. Attributes are used to define context switching. They are also used for naming and typing properties as shown in the previous sections. Attributes are in a separate namespace so they do not need to be treated as reserved words in the default namespace.

Global attributes are defined in the configuration namespace and must always be prefixed with config: . All attributes are optional. Most can be used with both resource and property elements but some can only be used with one type of element which is specified in the schema files.

The type of an element is defined using the config:type attribute. The type of a resource element is always RESOURCE, although this can also be made explicit with this attribute (to ensure correct identification of an empty element, for example, when there is no schema file to refer to). A resource element cannot be any other type and this restriction is specified in the schema file. The type of a property element determines the interpretation of its literal value. The type of a property element defaults to STRING, as specified in the schema file. The full set of permissible types is specified in the schema file.

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